Integrated scr reducing agent storage device

ABSTRACT

The invention discloses an integrated SCR reducing agent storage device. The integrated SCR includes a liquid storage box and a metering injection unit, the liquid storage box is used for storing reducing agent, the metering injection unit is integrated with the liquid storage box, the metering injection unit at least includes a pump body, and a membrane pump, a filter, a metering valve and a control unit all arranged on the pump body, and the metering injection unit is integrally arranged on the liquid storage box to inject the reducing agent under the control of the control unit, thus avoiding the use of pipes for suction, reflux and heating and of relevant pipe joints and decreasing the leakage risk of the reducing agent, meanwhile, the metering injection device is compact in structure, good is pressure stabilizing effect and accurate in control for injection of the reducing agent.

TECHNICAL FIELD

The invention relates to a reducing agent storage and injection controldevice in a diesel exhaust treatment purification system, in particularto a reducing agent storage device in an integrated SCR (SelectiveCatalyst Reaction) system.

BACKGROUND

With the increasing social requirement on environmental protection, ourcountry has put more and more efforts into environmental protection andappropriate polices regarding vehicle emission have been put forward byrelevant national departments, and especially, introduction of ‘NationalStandard IV’ results in more stringent control for vehicle emission,which means that the standard can be met only after 30%-50% of pollutantis reduced on the basis of ‘National Standard IV’, and ‘NationalStandard IV’ will come into force nationwide on 2012 in accordance withnormal standard implementation procedure.

Now, it is acknowledged that the technology of selective catalyticreduction (SCR) has dominated among vehicle emission post-treatmenttechnologies, that is, a reducing agent (referred to as ‘Ad-Blue’ inthis field) is quantitatively injected into an exhaust pipe byatomization and the primary harmful gas NOX in exhaust gas is convertedthrough an SCR catalyst into nitrogen and water which are thendischarged out, thus the purpose of exhaust purification is achieved,and this is also the commonest technical route for reaching the‘National Standard IV’.

An SCR system generally includes a urea box, a metering injection pump,a nozzle and the like, however in the prior art, the modular units aboveare all independent of each other, just as disclosed in the China patentCN101240729A entitled Diesel Vehicle Emission and Urea Box Reactor, andconnection among the urea box, the metering injection pump and otherdevices is realized by means of pipes and pipe joints. This typicallywill lead to the shortcomings below:

1. Mutual independence of the units and a large number of pipes(including pipes for suction, reflux and the like) result in greatdifficulty in arrangement, and pipe junctions are liable to be polluted,which brings difficult protection and also the hidden risk of leakage.

2. There is a high possibility of icing the reducing agent in variouspipes under an environment with a relatively low temperature, and icemelting is difficult.

3. The system cost is high, and a large arrangement space is required bythe units.

4. During practical mounting on vehicle, the matching effect in assemblyis poor because the units are independent of each other and provided bydifferent manufacturers, and pipe connection is carried out after allthe units are properly mounted, which causes great difficulty inmounting and high possibility of pollution.

SUMMARY OF THE INVENTION

The objective of the invention is to overcome the shortcomings in theprior art and provides an integrated SCR reducing agent storage devicewith high degree of integration, compact structure, good easiness in icemelting and great convenience for maintenance.

To fulfill the objective above, the technical proposal below ispresented in the invention: the integrated SCR reducing agent storagedevice includes a liquid storage box and a metering injection unit, theliquid storage box is used for storing reducing agent, and the meteringinjection unit is integrated with the liquid storage box.

Preferably, the integrated SCR reducing agent storage device furtherincludes a transition plate, and the metering injection unit isintegrated with the liquid storage box via the transition plate.

The integrated SCR reducing agent storage device includes a waterheating unit for heating the liquid storage box and the meteringinjection unit.

The metering injection unit further includes a cover body, a pump body,a membrane pump, a filter and a metering valve, the cover body isbuckled on the pump body, a closed space is formed between the coverbody and the pump body, and the membrane pump is at least arranged inthe closed space.

The integrated SCR reducing agent storage device further includes atransition plate, and the metering injection unit is integrated with theliquid storage box via the transition plate.

The metering injection unit includes a water heating unit, the waterheating unit is downwards extended into the liquid storage box from thetransition plate and is used for heating the liquid storage box and themetering injection unit.

The water heating unit includes a water inlet pipe, a water outlet pipe,and a water circulation pipe arranged in the metering injection unit,the pipes are connected with each other, and the water inlet pipe andthe water outlet pipe are extended into the liquid storage box.

The water heating unit further includes a water inlet joint and a wateroutlet joint, the water inlet joint and the water outlet joint arearranged on the pump body, and the water inlet joint, the water inletpipe, the water outlet pipe, the water circulation pipe and the wateroutlet joint are communicated with each other.

The integrated SCR reducing agent storage device further includes asensing component arranged in the liquid storage box, and the sensingcomponents is composed of a liquid level sensor and a first temperaturesensor.

The heat insulating sleeve is further arranged on the water inlet pipe.

A multi-section liquid flow pipe for circulation of the reducing agentis formed in the pump body.

The metering injection unit further includes a first pressure sensor anda second pressure sensor arranged at the two ends of the metering valve.

The metering injection unit further includes a control unit, and thecontrol unit is electrically connected with the membrane pump and themetering valve to control injection of the reducing agent.

The integrated SCR reducing agent storage device further includes asecond temperature sensor arranged in the pump body.

Compared with the prior art, the integrated SCR reducing agent storagedevice of the invention has the advantages:

1) superior design scheme and high degree of integration;

2) the use of pipes for suction, reflux and heating and of relevant pipejoints is avoided and the leakage risk of the reducing agent isdecreased;

3) heated engine cooling water passes by the metering pump and theliquid storage box directly, which avoids using a water heating deviceor an electric heating device for heating the metering pumpindependently;

4) a heat insulating sleeve is wrapped on the upper portion of the waterinlet pipe to heat the reducing agent at the bottom at first, whichbrings good heating effect and helps timely ice melting and suction ofthe reducing agent;

5) the metering pump and the urea box are structurally integrated, sothe occupied space is small and the cost is relatively low, meanwhile,convenient disassembly and mounting and excellent matching effect areachieved due to the modularized arrangement.

6) a filtration cavity and a pressure stabilizing cavity are integrallydesigned, thus bringing compact structure and good pressure stabilizingeffect and contributing to control for the metering valve;

7) a cyclone mixing cavity is employed to achieve the purposes of smallpressure loss, good stirring and atomization effects and low possibilityof crystallization blockage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a stereogram of the integrated SCR reducing agent storagedevice of the invention;

FIG. 2 is an exploded stereogram of FIG. 1;

FIG. 3 is a wiring diagram of the integrated SCR reducing agent storagedevice of the invention;

FIG. 4 is an exploded stereogram of the filter in FIG. 3;

FIG. 5 is a partial sectional view of connection among the filter, themetering valve and the mixing cavity in the invention;

FIG. 6 is a sectional view in a CC direction of FIG. 5;

FIG. 7 is a bottom view of the pump body in the integrated SCR reducingagent storage device of the invention;

FIG. 8 is a top view of the pump body in the integrated SCR reducingagent storage device of the invention;

FIG. 9 is a stereogram of the transition plate in the invention;

FIG. 10 is a wiring diagram of the embodiment 2 of the integrated SCRreducing agent storage device of the invention;

FIG. 11 is a wiring diagram of the embodiment 3 of the integrated SCRreducing agent storage device of the invention.

REFERENCE NUMERALS OF ELEMENTS IN THE DRAWINGS metering 1 cover body 11pump body 12 injection unit lower surface of 121 membrane 13 the firstpressure 14 the pump body pump sensor the second 15 liquid flow pipe 16control unit 17 pressure sensor annular groove 161 liquid outlet 18sensing 19 joint component liquid storage 2 transition plate 3 boxsuction pipe 31 filter 4 filter cavity shell 41 end cover 42 filter core43 liquid inlet 44 liquid outlet 45 metering valve 5 mixing cavity 6 airthrottle 61 check valve 71 membrane valve 72 orifice the first 73 thethird 74 through hole 75 electromagnetic electromagnetic valve valvenozzle 76 exhaust pipe 77 ventilation pipe 79 water heating 8 waterinlet joint 81 water inlet pipe 82 unit water outlet pipe 83 wateroutlet 84 water circulation 85 joint pipe the first flow 86 heatexchanger 87 heat insulating 88 passage sleeve compressed air 9 airsource 91 the second 92 unit electromagnetic valve reducing valve 93 thesecond 94 rough filtration 32 temperature device sensor

DETAILED DESCRIPTION OF THE EMBODIMENTS

The technical proposal in the preferred embodiment of the invention willbe described below in a clear and complete way with reference to thedrawings of the invention.

As shown in FIG. 1 and FIG. 2, the integrated SCR reducing agent storagedevice of the invention includes a metering injection unit 1 and aliquid storage box 2, the metering injection unit 1 is integrated withthe liquid storage box 2 via a transition plate 3, and the meteringinjection unit includes a cover body 11, a pump body 12, a membrane pump13, a filter 4, a metering valve 5, a mixing cavity 6, a first pressuresensor 14, a second pressure sensor 15, a liquid flow pipe 16 arrangedon the pump body and a control unit 17.

As shown in FIG. 3, the cover body 11 is buckled on the pump body 12, aclosed space is formed between the cover body 11 and the pump body 12,the membrane pump 13, the metering valve 5, the mixing cavity 6, thefirst pressure sensor 14 and the second pressure sensor 15 are allarranged in the closed space formed between the cover body 11 and thepump body 12, the filter 4 is arranged on the pump body 12 at the outerside of the cover body 11 for the purpose of facilitating cleaning andmaintenance; the membrane pump 13 is used for sucking the reducing agentfrom the liquid storage box 2 to the liquid flow pipe 16 of the pumpbody, in order to offer a power source to convey the reducing agent.

In the metering injection unit as shown in FIG. 4 to FIG. 6, the filter4 is fixedly mounted on the pump body 12 and is used for filtering andinhibiting pressure fluctuation, the filter 4 includes a filter cavityshell 41, an end cover 42 and a filter core 43 arranged in the filtercavity shell and the end cover, the filter cavity shell 41 is integrallyformed on the pump body 12, the end cover 42 is arranged, in a sealingmanner, on one end of the filter cavity shell 41, a liquid inlet 44 anda liquid outlet 45 are arranged on the filter cavity shell 41, and theliquid outlet 45 is communicated with the liquid inlet of the meteringvalve 5 via the liquid flow pipe 16 arranged in the pump body. As shownin FIG. 4, the liquid inlet 44 of the filter 4 is arranged in adirection tangent to the inner wall of the filter cavity shell 41 of thefilter, and such a tangent arrangement of the liquid inlet isimplemented to avoid damage to the filter core, which is caused by thefact that, due to vertical arrangement of the liquid inlet and thefilter cavity shell 41, the filter core is directly impacted by thereducing agent under excessive pressure; meanwhile, the reducing agententers a liquid storage cavity in a manner of deviating from the coreshaft direction and then flows in a wall adherence manner to createcushion, thus preventing obvious pressure fluctuation generated byliquid disturbance under vertical entrance of the reducing agent, andplaying a role of pressure stabilization.

As shown in FIG. 5 and FIG. 7, a high-precision metering valve dedicatedto urea is used as the metering valve 5 in this embodiment and is usedfor metering injection of the reducing agent. One end of the meteringvalve 5 is connected with the filter 4 via a through hole 75 and theliquid flow pipe 16 in the pump body, while the other end thereof isconnected with the mixing cavity 6, which is connected in series at thedownstream of the metering valve 5 and mainly has the function of mixingatomization for air-liquid, in order to form homogeneous suspension andoptimize purification effect.

In this embodiment, an injection hole portion at one end of the meteringvalve 5 stretches into the mixing cavity 6, an air throttle orifice 61is arranged on the inner wall of the mixing cavity 6, the other end ofthe air throttle orifice is communicated with an air source, the airthrottle orifice 61 is tangent to the inner wall of the mixing cavity 6and provides an inlet of compressed air source for air-liquid mixing inthe mixing cavity 6, and in the process of injecting the reducing agentby the metering valve 5, a high-speed airflow tangentially enters themixing cavity 6 via the air throttle orifice 61.

Based on the principle of cyclone separator, when a tangent airflowenters the mixing cavity 6, an outward rotation airflow and an inwardrotation airflow are formed in the cavity, the outward rotation airflowis rotated in a manner of cavity wall adherence and is blown in adirection away from the liquid outlet joint, i.e. in a direction towardsthe metering valve 5, the inward rotation airflow, which moves in adirection opposite to the outward rotation airflow, is formed when thetangent airflow reaches the top of the mixing cavity 6, at the sametime, when the airflows are converged at the injection hole of themetering valve 5, the injected reducing agent is fully stirred by theinward rotation airflow under the action of the injection pressure fromthe metering valve and is then blown downwards and injected out throughthe liquid outlet joint, urea aqueous solution can be formed intohomogeneous suspension due to the stirring effect in the mixing cavity6, thus reducing the crystallization risk and contributing to forminghomogeneous spray at an atomization nozzle at the downstream of theliquid outlet joint so as to improve the effect of selective catalyticreaction.

One end of the mixing cavity 6, which is far away from the meteringvalve 5, is communicated with the liquid outlet joint 18 on the sidewallof the pump body via the liquid flow pipe 16 in the pump body, and theliquid outlet joint 18 is connected with an exhaust pipe 77 via aninjection pipe and a nozzle 76. Preferably, the position of the liquidoutlet joint 18 is lower than that of the metering valve 5, an acuteangle is formed between the axis of the mixing cavity 6 and thehorizontal direction, that is to say, the mixing cavity 6 is arrangedobliquely, preferably a 20-degree angle formed between the mixing cavity6 and the horizontal direction, in this way, after the injectionoperation comes to an end, the reducing agent is not refluxed to blockoff the injection hole of the metering valve, instead, it flowsdownwards (i.e. the direction of the liquid outlet joint) under theaction of gravity even if there is reducing agent remaining in themixing cavity.

As shown in FIG. 7 and FIG. 8, the liquid flow pipe 16 consists ofmultiple sections of pipes that are arranged at the inner side of thepump body 12 and in the space between the lower surface 121 of the pumpbody and the transition plate 3 in a penetrating manner, the membranepump 13, the filter 4 and the metering valve 5 are sequentiallycommunicated with each other via the liquid flow pipe 16 in the pumpbody, one end of the liquid flow pipe 16 is connected with a suctionpipe 31 extending downwards from the lower side of the transition plate3 and then sequentially connected with the membrane pump 13 and a checkvalve 71 mounted on the pump body 12 to be divided into two flowpassages, one of the flow passages is connected with the liquid inlet 44of the filter 4 via the through hole 75 penetrating through the pumpbody in the drawing and via an annular groove 161, so that the reducingagent that needs to be injected is conveyed into the filter 4 and thenfiltered, and finally conveyed into the metering valve 5; the other flowpassage forms a liquid reflux pipe connected with a membrane valve 72and the liquid storage box, as shown in FIG. 10, and the bottom of thesuction pipe 31 is connected with a rough filtration device 32 in orderto prevent blockage in the injection system caused by entrance of theimpurities in the reducing agent.

As shown in FIG. 2, FIG. 3, FIG. 7 and FIG. 9, the integrated SCRreducing agent storage device of the invention further includes a waterheating unit 8, the water heating unit 8 uses heated engine coolingwater in a recycling manner, so the reducing agent in the meteringinjection unit and the liquid storage box can be heated in cold seasons,meanwhile, the heated engine cooling water flows circularly inside thewater circulation pipe to heat the pump body 12.

The water heating unit 8 includes a water inlet joint 81, a water inletpipe 82, a water outlet pipe 83, a water outlet joint 84 and amulti-section water circulation pipe 85, the water circulation pipe 85includes a first flow passage 851 and a second flow passage 852 botharranged inside the pump body 12, and a third flow passage 853 formedbetween the lower surface 121 of the pump body 12 and the transitionplate 3, and the first flow passage 851 and the second flow passage 852are respectively connected with the water inlet joint 81 and the wateroutlet joint 84 arranged on the sidewall of the pump body.

The water inlet pipe 82 and the water outlet pipe 83 are formed in amanner of extending downwards from the lower side of the transitionplate 3, the upper ends of the both are communicated with the third flowpassage 853 of the water circulation pipe 85 respectively and thebottoms of the both are communicated with each other through a heatexchanger 87, and the water inlet joint 81, the water inlet pipe 82, thewater outlet pipe 83 and the water outlet joint 84 are communicated witheach other in sequence through the water circulation pipe 85 in order toimpart a good heating on the reducing agent in the pump body 12 and theliquid storage box 2.

Preferably, the heat exchanger 87, which is formed on the bottom of theliquid storage box at the junction of the water inlet pipe 82 and thewater outlet pipe 83, is a spiral structure for increasing the heatingarea, a heat insulating sleeve 88 is wrapped on the outer surface of theupper portion of the water inlet pipe 82, and the heat insulating sleeve88 is arranged to avoid, when the heated cooling water flows by theupper portion of the water inlet pipe, loss of excessive heat, which inturn melts the ice at the bottom of the urea box at first in order tocontribute to suction.

More preferably, the metering injection device of the invention furtherincludes a ventilation pipe 79, and the ventilation pipe 79, the suctionpipe 31 and the water inlet pipe 82 are all wrapped in the heatinsulating sleeve 88.

As shown in FIG. 3, a first electromagnetic valve 73 is further arrangedon the pipeline of the water inlet pipe in the water heating unit 8, thefirst electromagnetic valve 73 is electrically connected with thecontrol unit 17, and the control unit 17 controls the heated coolingwater to perform cyclic heating and ice melting by controlling the firstelectromagnetic valve 73.

The control unit 17 is electrically connected with the membrane pump 13,the metering valve 5, and the first pressure sensor 14 and the secondpressure sensor 15 mounted on the two ends of the metering valve 5 andthe mixing cavity 6, wherein the first pressure sensor 14 is arranged atthe upstream end of the metering valve 5, the second pressure sensor 15is arranged at the downstream end of the metering valve 5, and accordingto a specified injection amount received by the control unit and apressure difference between the two ends of the metering valve, thefirst pressure sensor 14 and the second pressure sensor 15 calculate theduty ratio of the starting pulse of the metering valve 5 to achieve thepurpose of accurate metering.

The metering injection device in this embodiment further includes acompressed air unit 9, the compressed air unit 9 includes an air source91, a second electromagnetic valve 92 and a reducing valve 93 which areserially connected in sequence, the second electromagnetic valve 92 isin circuit connection with the control unit 17, an air filter is furtherarranged at the downstream of the air source 91, the compressed air unitcan not only provide air pressure for opening or closing of the membranevalve 71, but also provide compressed air for atomization of thereducing agent in the mixing cavity 6.

As shown in FIG. 3 and FIG. 9, the metering injection device of theinvention further includes a sensing component 19, the sensing component19 is composed of a displacement sensor and a first temperature sensor,the sensing component and the water heating unit are integrated belowthe metering injection unit, the sensing component is electricallyconnected with the control unit in the metering injection unit, and thesensing component provides sensed information regarding liquid level andtemperature in the liquid storage box. More preferably, a secondtemperature sensor 94 for measuring the reducing agent in the pump bodyis further mounted in the pump body 12.

When the control unit receives an engine ignition signal, the controlunit 17 controls a motor in the membrane pump 13 to begin an emptyingaction at a certain fixed rotating speed, so that the reducing agent inthe liquid flow pipe 16 is returned to the liquid storage box 2 througha reflux pipe, and about 30 seconds later, the control unit 17 controlsthe second electromagnetic valve 72 to open the air source and close anemptying loop, the membrane pump 13 continues working at this moment,the reducing agent is conveyed to the upstream of the metering valve 5by the pump body after passing through the liquid flow pipe 16 and thefilter 4, the pressure of the reducing agent increases ceaselessly, themotor of the membrane pump stops operating when a pressure value P1 ofthe first pressure sensor 14 at the upstream of the metering valve 5reaches a set value, the control unit receives an injection request andcontrols the metering valve 5 to begin metering injection, and thesecond pressure sensor 15 is used for acquiring a pressure value P2 atthe downstream of the metering valve to calculate the pressuredifference, and for regulating the opening pulse width of the meteringvalve.

The pressure value (P1) of the first pressure sensor 14 is relativelysmall after the control unit 17 controls the compressed air unit toclose a liquid return membrane and before injection, at this moment, thecontrol unit 17 controls the motor in the membrane pump to operate at apreset rotating speed, and about 5 seconds later, the pressure value P1in the filtration cavity reaches an injection pressure value; P1 willdecrease after injection begins, specifically depending on the injectionamount, and in order to keep P1 stable, the motor begins working and thereducing agent is supplemented into the filtration cavity to keep the P1value stable, furthermore, during this procedure, the rotating speed ofthe motor is subjected to closed-loop control in accordance with theinjection amount and the current P1 value, so as to achieve the purposeof accurate metering.

When heating is needed at a relatively low temperature, the control unit17 controls the second electromagnetic valve 92 to open the waterheating unit after receiving a low temperature signal from thetemperature sensor in inductive sensors, the heated engine cooling waterflows by the water inlet joint 81, the water inlet pipe 82, the wateroutlet pipe 83 and the water outlet joint 84 in sequence, which realizesheating not only for the metering injection unit, but also for thereducing agent in the liquid storage box 2.

FIG. 10 is a system control diagram of the embodiment 2 of theinvention, an air injection system is involved in both this embodimentand the embodiment 1, which have the difference that the pipe of thenozzle 76 at the downstream of the metering injection unit 1 iscommunicated with the compressed air unit 9 to achieve the effect ofsecondary atomization.

FIG. 11 is a system control diagram of the embodiment 3 of theinvention, an airless injection system is involved in this embodiment,and the difference between this embodiment and the embodiment 1 consistsin the fact that no compressed air unit is required in this embodiment,the reducing agent is directly injected into the exhaust pipe 77 by themetering valve 5, and on the reflux pipe, a third electromagnetic valve74 is in direct circuit connection with the control unit 17, whichdirectly controls opening and closing of the third electromagnetic valve74 to control reflux and further finish the emptying operation.

The technical contents and features of the invention have been disclosedabove, however, a variety of substitutions and modifications notdeparting from the spirit of the invention may still be made by thoseskilled familiar with the art based upon the instruction and disclosureof the invention, thus, the scope of the invention shall not be limitedto the contents disclosed in the embodiments, instead, it shall includea variety of substitutions and modifications that do not depart from theinvention and is covered by the claims of this patent application.

1. An integrated SCR reducing agent storage device, characterized inthat: the integrated SCR reducing agent storage device includes a liquidstorage box and a metering injection unit, the liquid storage box isused for storing reducing agent, and the metering injection unit isintegrated with the liquid storage box.
 2. The integrated SCR reducingagent storage device according to claim 1, characterized in that: theintegrated SCR reducing agent storage device further includes atransition plate, and the metering injection unit is integrated with theliquid storage box via the transition plate.
 3. The integrated SCRreducing agent storage device according to claim 1, characterized inthat: the integrated SCR reducing agent storage device includes a waterheating unit for heating the liquid storage box and the meteringinjection unit.
 4. The integrated SCR reducing agent storage deviceaccording to claim 1, characterized in that: the metering injection unitfurther includes a cover body, a pump body, a membrane pump, a filterand a metering valve, the cover body is buckled on the pump body, aclosed space is formed between the cover body and the pump body, and themembrane pump is at least arranged in the closed space.
 5. Theintegrated SCR reducing agent storage device according to claim 4,characterized in that: the integrated SCR reducing agent storage devicefurther includes a transition plate, and the metering injection unit isintegrated with the liquid storage box via the transition plate.
 6. Theintegrated SCR reducing agent storage device according to claim 5,characterized in that: the metering injection unit includes a waterheating unit, the water heating unit is downwards extended into theliquid storage box from the transition plate and is used for heating theliquid storage box and the metering injection unit.
 7. The integratedSCR reducing agent storage device according to claim 6, characterized inthat: the water heating unit includes a water inlet pipe, a water outletpipe, and a water circulation pipe arranged in the metering injectionunit, the pipes are connected with each other, and the water inlet pipeand the water outlet pipe are extended into the liquid storage box. 8.The integrated SCR reducing agent storage device according to claim 7,characterized in that: the water heating unit further includes a waterinlet joint and a water outlet joint, the water inlet joint and thewater outlet joint are arranged on the pump body, and the water inletjoint, the water inlet pipe, the water outlet pipe, the watercirculation pipe and the water outlet joint are communicated with eachother.
 9. The integrated SCR reducing agent storage device according toclaim 7, characterized in that: the integrated SCR reducing agentstorage device further includes a sensing component arranged in theliquid storage box, and the sensing components is composed of a liquidlevel sensor and a first temperature sensor.
 10. The integrated SCRreducing agent storage device according to claim 7, characterized inthat: a heat insulating sleeve is further arranged on the water inletpipe.
 11. The integrated SCR reducing agent storage device according toclaim 4, characterized in that: a multi-section liquid flow pipe forcirculation of the reducing agent is formed in the pump body.
 12. Theintegrated SCR reducing agent storage device according to claim 4,characterized in that: the metering injection unit further includes afirst pressure sensor and a second pressure sensor arranged at the twoends of the metering valve.
 13. The integrated SCR reducing agentstorage device according to claim 4, characterized in that: the meteringinjection unit further includes a control unit, and the control unit iselectrically connected with the membrane pump and the metering valve tocontrol injection of the reducing agent.
 14. The integrated SCR reducingagent storage device according to claim 4, characterized in that: theintegrated SCR reducing agent storage device further includes a secondtemperature sensor arranged in the pump body.